Stinker and the little fawn were great rewards with unique models, I'm confident Nuts will be more than a recolored mechanical squirrel.

If you exclude promotional pets (i.e. collector's edition or blizzcon pets), TCG pets, blizz store pets (and the core hound because not everyone can get an authenticator for free), and pets that are no longer obtainable there are currently 143 pets in the game (according to the pet collection data on wowhead profiler). I assume 4.2 will add several, but currently it's pretty improbable that someone would be able to get 150 pets without spending money on them in some way.

Yep, I was looking at the same thing. 150 mini-pets is a difficult feat!

If those have charges I guarantee you I will use them once and then keep them in my bank not to waste them =/

Neirin, there are over 170 pets in game right now (a few are region restricted). My paladin is currently at 144 with 30 others still available on my wanted list.

Purples are fun for an expansion, but pets and mounts are forever. :)

My main has 135 pets right now, and the remaining fifteen are all obtainable without shelling out real money. I've only purchased three pets - two of the charity pets and one Li'l Rag. And I refuse to ever buy the cockroach.

So it can be done.